File Name: structure and pumping action of heart .zip
The heart pumps blood through the body with the help of structures such as ventricles, atria, and valves. The heart is a complex muscle that pumps blood through the three divisions of the circulatory system: the coronary vessels that serve the heart , pulmonary heart and lungs , and systemic systems of the body.
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. The wall of the heart is made up of three layers: epicardium , myocardium , and endocardium. The heart pumps blood with a rhythm determined by a group of pacemaking cells in the sinoatrial node. These generate a current that causes contraction of the heart, traveling through the atrioventricular node and along the conduction system of the heart. The heart receives blood low in oxygen from the systemic circulation , which enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle. From here it is pumped into the pulmonary circulation , through the lungs where it receives oxygen and gives off carbon dioxide.
The cardiovascular system can be thought of as the transport system of the body. This system has three main components: the heart , the blood vessel and the blood itself. Blood can be thought of as a fluid which contains the oxygen and nutrients the body needs and carries the wastes which need to be removed. The following information describes the structure and function of the heart and the cardiovascular system as a whole. The heart is located in between the two lungs.
The human heart is a four-chambered muscular organ , shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of midline. The heart is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane. The visceral layer of the serous membrane forms the epicardium. Three layers of tissue form the heart wall. The outer layer of the heart wall is the epicardium, the middle layer is the myocardium , and the inner layer is the endocardium. The internal cavity of the heart is divided into four chambers:. The two atria are thin-walled chambers that receive blood from the veins.
Blood must always circulate to sustain life. It carries oxygen from the air we breathe to cells throughout the body. The pumping of the heart drives this blood flow through the arteries, capillaries, and veins. One set of blood vessels circulates blood through the lungs for gas exchange. The other vessels fuel the rest of the body.
Jump to content. The heart is at the center of your circulatory system, which is a network of blood vessels that delivers blood to every part of your body. Blood carries oxygen and other important nutrients that all body organs need to stay healthy and to work properly. Your heart has four separate chambers that pump blood, two on the right side and two on the left. Blood flows through your heart and lungs in four steps:. The left and right atria are smaller chambers that pump blood into the ventricles.
Some changes in the heart and blood vessels normally occur with age. However, many other changes that are common with aging are due to or worsened by modifiable factors. If not treated, these can lead to heart disease.
The cardiovascular system is a closed system if the heart and blood vessels. The heart pumps blood through a closed system of blood vessels. Blood vessels allow blood to circulate to all parts of the body. The vital importance of the heart is obvious. If one assumes an average rate of contraction of 75 contractions per minute, a human heart would contract approximately , times in one day, more than 39 million times in one year, and nearly 3 billion times during a year lifespan.
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Your heart is roughly the size of a fist and sits in the middle of your chest, slightly to the left.Popnoigicom 23.05.2021 at 21:57
A number of structures that can be observed in the adult heart are remnants of fetal circulation. In the fetus, the lungs do not function as a site for the exchange of.